Myeloablative and Reduced-Intensity Conditioned Allogeneic Hematopoietic Stem Cell Transplantation in Myelofibrosis: A Retrospective Study by the Chronic Malignancies Working Party of the European Society for Blood and Marrow Transplantation

• Published in: Biology of blood and marrow transplantation 2019-11, Vol.25 (11), p.2167-2171
• Main Authors: McLornan, Donal, Szydlo, Richard, Koster, Linda, Chalandon, Yves, Robin, Marie, Wolschke, Christine, Beelen, Dietrich, Socié, Gerard, Bornhäuser, Martin, Angelucci, Emanuele, Niederwieser, Dietger, Gerbitz, Arnim, Finke, Jürgen, Vitek, Antonin, Itälä-Remes, Maija, Radujkovic, Aleksandar, Kanz, Lothar, Potter, Victoria, Chevallier, Patrice, Stelljes, Matthias, Petersen, Eefke, Robinson, Stephen, Poiré, Xavier, Klyuchnikov, Evgeny, Hernández-Boluda, Juan Carlos, Czerw, Tomasz, Hayden, Patrick, Kröger, Nicolaus, Yakoub-Agha, Ibrahim
• Format: Article
• Language: English
• Subjects: Myeloablative; Myeloproliferative; Reduced intensity; Stem cell transplantation
• ISSN: 1083-8791; 1523-6536
• DOI: 10.1016/j.bbmt.2019.06.034

•In this largest cohort of myelofibrosis transplants analyzed to date, no significant difference in 5-year probabilities of overall survival (OS) was noted between those undergoing myeloablative conditioning (MAC) (53.0%; 95% confidence interval [CI], 49.1% to 56.9%) and reduced-intensity conditioning (RIC) (51.0%; 95% CI, 48.3% to 53.7%); P = .78.•Graft failure rates appeared higher in those undergoing RIC protocols compared with MAC protocols.•MAC platforms demonstrated a trend toward less relapse and significantly improved graft-versus-host disease-free/relapse-free survival, although this requires validation. This retrospective study by the European Society for Blood and Marrow Transplantation analyzed the outcome of 2224 patients with myelofibrosis (MF) who underwent allogeneic stem cell transplantation (allo-SCT) between 2000 and 2014; 781 (35%) underwent myeloablative conditioning (MAC) and 1443 (65%) reduced-intensity conditioning (RIC). Median patient age was 52.9 years (range, 18 to 74 years) and 57.5 years (range, 21 to 76 years) in the MAC and RIC cohorts, respectively. Donor type was similar: matched sibling donors (MAC, 317 [41%]; RIC, 552 [38%]) and unrelated donors (MAC, 464 [59%]; RIC, 891 [62%]). Median time to both neutrophil and platelet (>20 × 109/L) engraftment did not differ between cohorts. Rates of grade II to IV acute GVHD were 28% (MAC) and 31% (RIC; P = NS). Cumulative chronic GVHD rates (limited/extensive) were 22%/27% (MAC) and 19%/31% (RIC; P = .10). Cumulative incidences of nonrelapse mortality (NRM) at 1, 3, and 5 years were 25.5%, 32.2%, and 34.6% (MAC) and 26.3%, 32.8%, and 34.4% (RIC), respectively. There was a trend toward a higher relapse rate with RIC regimens compared with MAC (P = .08); rates at 1, 3, and 5 years were 10.9%, 17.2%, and 20.1% (MAC) and 14%, 19.7%, and 23.2% (RIC), respectively. No significant difference in 5-year probabilities of overall survival (OS) was noted: MAC (53.0%; 95% confidence interval [CI], 49.1% to 56.9%) and RIC (51.0%; 95% CI, 48.3% to 53.7%); P = .78. Regarding the composite end point of GVHD-free/relapse-free survival (GRFS), the unadjusted Kaplan-Meier estimate of 5-year GRFS was 32.4% (95% CI, 29.0% to 36.1%) in the MAC group and 26.1% (95% CI, 23.9% to 28.2%) in the RIC group (P = .001). In the MAC cohort, multivariable analysis confirmed worse OS and NRM with older age (>50 years), using an unrelated donor and a Karnofsky Performance Status of 80 or less. For the RIC cohort, wor